All grazing cattle will benefit from a mineral supplementation program. The challenge is figuring out what they are getting from the forage base, what they need, and how best to deliver a supplement product that fills the gaps to meet their needs, but doesn’t create problems (often unseen and unknown) by delivering too much of something.
The challenge is that “what they are getting” and “what they need” are constantly changing throughout the year. Forage mineral composition varies by soil type, forage species and maturity, current growing conditions, fertilization history, grazing management and so on. Then a beef cow’s requirements for minerals fluctuate with the stages of production. Everything is a moving target.
It’s a little like trying to figure out if the fish scale reads 93 lbs. vs. 94 lbs. while new baby’s momma is doing a great job convincing you that she is not bluffing. Mineral nutrition is not that exciting although perhaps similar in the sense that calf birth weight records, even if not perfect every time, have proven to be a powerful source of information over the years.
A great tool to evaluate the mineral program is to conduct one or multiple mineral balance exercises. Especially early on in this process, producers should consider engaging their Extension educator, veterinarian or a feed industry expert to assist or advise. A mineral balance exercise involves developing a simple, consistent recordkeeping system to track critical pieces of information; forage mineral composition during that time of year and your cow herds’ average or “normal” mineral consumption pattern during that same time of year.
Mineral balance exercises could be conducted as few times as once during the grazing season and once for the winter-feeding period, or they can be completed on a quarterly or even a monthly basis. Several commercial nutrition companies provide services to conduct these balance exercises and follow up by recommending or manufacturing mineral formulations customized to your operation’s needs. You can find a handy phone app to track mineral consumption at: beef.okstate.edu/pages/calculators.
Most commercial livestock nutrition laboratories provide forage mineral composition analytical services for a reasonable fee. For example, the lab at Oklahoma State University (OSU) charges $12 per sample to get macro and micro minerals. One might get started by simply sampling and testing harvested hay or silage each year and developing a spreadsheet where you can easily access and summarize those records over time.
A more ambitious approach might be to collect “hand-plucked” samples from one or more pastures each month. The idea of the hand-plucking method is to select only plants and parts of plants that you believe to represent what your cattle are currently grazing.
The OSU Cowculator nutrition evaluation program is a great tool to simplify a mineral balance exercise. The feed library allows one to enter their own forage nutritive values and mineral supplement products/formulations. The “Balance” page provides guidance to estimate daily forage consumption and then a place to input the amount of mineral the cows are expected to consume. From there, a table is provided showing you the difference between “what they are getting” and “what they need.”
Consider collecting forage mineral composition data and mineral supplement consumption data several years in a row to see the variation (or maybe the consistency) of those patterns over time. Finally, use that valuable information to conduct mineral balance exercises for the different seasons. This should lead to you having confidence that your cattle are getting what they need when they need it and potentially to cost savings. — David Lalman, OSU Extension specialist
